In one aspect, this invention relates to a process for preparing compositions of matter which contain alumina as the major component and silica as a minor component. In another aspect, this invention relates to compositions that contain alumina as the major component and silica as a minor component, said compositions possessing high surface area and high pore volume. In a further aspect, this invention relates to compositions that contain alumina as the major component, silica as a minor component and, additionally, hydrotreating promoter(s). In still another aspect, this invention relates to a process for hydrotreating liquid hydrocarbon-containing feed streams, which contain sulfur and metal impurities, in the presence of a catalyst composition comprising alumina as the major component and silica as a minor component.
Numerous processes for making alumina-silica compositions, suitable as catalysts or catalyst supports, are known. Some of these processes, such as those disclosed in U.S. Pat. Nos. 3,925,253 and 3,923,692, produce silica-coated alumina materials suitable as hydrotreating support materials for catalysts. However, there is an ever present need to develop new silica-modified alumina materials having a desirably high surface area and high pore volume, suitable for use in heavy oil hydrotreating processes.